xref: /linux/drivers/target/target_core_pscsi.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*******************************************************************************
2  * Filename:  target_core_pscsi.c
3  *
4  * This file contains the generic target mode <-> Linux SCSI subsystem plugin.
5  *
6  * (c) Copyright 2003-2013 Datera, Inc.
7  *
8  * Nicholas A. Bellinger <nab@kernel.org>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23  *
24  ******************************************************************************/
25 
26 #include <linux/string.h>
27 #include <linux/parser.h>
28 #include <linux/timer.h>
29 #include <linux/blkdev.h>
30 #include <linux/blk_types.h>
31 #include <linux/slab.h>
32 #include <linux/spinlock.h>
33 #include <linux/genhd.h>
34 #include <linux/cdrom.h>
35 #include <linux/ratelimit.h>
36 #include <linux/module.h>
37 #include <asm/unaligned.h>
38 
39 #include <scsi/scsi_device.h>
40 #include <scsi/scsi_host.h>
41 #include <scsi/scsi_tcq.h>
42 
43 #include <target/target_core_base.h>
44 #include <target/target_core_backend.h>
45 
46 #include "target_core_alua.h"
47 #include "target_core_internal.h"
48 #include "target_core_pscsi.h"
49 
50 #define ISPRINT(a)  ((a >= ' ') && (a <= '~'))
51 
52 static inline struct pscsi_dev_virt *PSCSI_DEV(struct se_device *dev)
53 {
54 	return container_of(dev, struct pscsi_dev_virt, dev);
55 }
56 
57 static sense_reason_t pscsi_execute_cmd(struct se_cmd *cmd);
58 static void pscsi_req_done(struct request *, int);
59 
60 /*	pscsi_attach_hba():
61  *
62  * 	pscsi_get_sh() used scsi_host_lookup() to locate struct Scsi_Host.
63  *	from the passed SCSI Host ID.
64  */
65 static int pscsi_attach_hba(struct se_hba *hba, u32 host_id)
66 {
67 	struct pscsi_hba_virt *phv;
68 
69 	phv = kzalloc(sizeof(struct pscsi_hba_virt), GFP_KERNEL);
70 	if (!phv) {
71 		pr_err("Unable to allocate struct pscsi_hba_virt\n");
72 		return -ENOMEM;
73 	}
74 	phv->phv_host_id = host_id;
75 	phv->phv_mode = PHV_VIRTUAL_HOST_ID;
76 
77 	hba->hba_ptr = phv;
78 
79 	pr_debug("CORE_HBA[%d] - TCM SCSI HBA Driver %s on"
80 		" Generic Target Core Stack %s\n", hba->hba_id,
81 		PSCSI_VERSION, TARGET_CORE_VERSION);
82 	pr_debug("CORE_HBA[%d] - Attached SCSI HBA to Generic\n",
83 	       hba->hba_id);
84 
85 	return 0;
86 }
87 
88 static void pscsi_detach_hba(struct se_hba *hba)
89 {
90 	struct pscsi_hba_virt *phv = hba->hba_ptr;
91 	struct Scsi_Host *scsi_host = phv->phv_lld_host;
92 
93 	if (scsi_host) {
94 		scsi_host_put(scsi_host);
95 
96 		pr_debug("CORE_HBA[%d] - Detached SCSI HBA: %s from"
97 			" Generic Target Core\n", hba->hba_id,
98 			(scsi_host->hostt->name) ? (scsi_host->hostt->name) :
99 			"Unknown");
100 	} else
101 		pr_debug("CORE_HBA[%d] - Detached Virtual SCSI HBA"
102 			" from Generic Target Core\n", hba->hba_id);
103 
104 	kfree(phv);
105 	hba->hba_ptr = NULL;
106 }
107 
108 static int pscsi_pmode_enable_hba(struct se_hba *hba, unsigned long mode_flag)
109 {
110 	struct pscsi_hba_virt *phv = hba->hba_ptr;
111 	struct Scsi_Host *sh = phv->phv_lld_host;
112 	/*
113 	 * Release the struct Scsi_Host
114 	 */
115 	if (!mode_flag) {
116 		if (!sh)
117 			return 0;
118 
119 		phv->phv_lld_host = NULL;
120 		phv->phv_mode = PHV_VIRTUAL_HOST_ID;
121 
122 		pr_debug("CORE_HBA[%d] - Disabled pSCSI HBA Passthrough"
123 			" %s\n", hba->hba_id, (sh->hostt->name) ?
124 			(sh->hostt->name) : "Unknown");
125 
126 		scsi_host_put(sh);
127 		return 0;
128 	}
129 	/*
130 	 * Otherwise, locate struct Scsi_Host from the original passed
131 	 * pSCSI Host ID and enable for phba mode
132 	 */
133 	sh = scsi_host_lookup(phv->phv_host_id);
134 	if (!sh) {
135 		pr_err("pSCSI: Unable to locate SCSI Host for"
136 			" phv_host_id: %d\n", phv->phv_host_id);
137 		return -EINVAL;
138 	}
139 
140 	phv->phv_lld_host = sh;
141 	phv->phv_mode = PHV_LLD_SCSI_HOST_NO;
142 
143 	pr_debug("CORE_HBA[%d] - Enabled pSCSI HBA Passthrough %s\n",
144 		hba->hba_id, (sh->hostt->name) ? (sh->hostt->name) : "Unknown");
145 
146 	return 1;
147 }
148 
149 static void pscsi_tape_read_blocksize(struct se_device *dev,
150 		struct scsi_device *sdev)
151 {
152 	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
153 	int ret;
154 
155 	buf = kzalloc(12, GFP_KERNEL);
156 	if (!buf)
157 		return;
158 
159 	memset(cdb, 0, MAX_COMMAND_SIZE);
160 	cdb[0] = MODE_SENSE;
161 	cdb[4] = 0x0c; /* 12 bytes */
162 
163 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf, 12, NULL,
164 			HZ, 1, NULL);
165 	if (ret)
166 		goto out_free;
167 
168 	/*
169 	 * If MODE_SENSE still returns zero, set the default value to 1024.
170 	 */
171 	sdev->sector_size = (buf[9] << 16) | (buf[10] << 8) | (buf[11]);
172 	if (!sdev->sector_size)
173 		sdev->sector_size = 1024;
174 out_free:
175 	kfree(buf);
176 }
177 
178 static void
179 pscsi_set_inquiry_info(struct scsi_device *sdev, struct t10_wwn *wwn)
180 {
181 	unsigned char *buf;
182 
183 	if (sdev->inquiry_len < INQUIRY_LEN)
184 		return;
185 
186 	buf = sdev->inquiry;
187 	if (!buf)
188 		return;
189 	/*
190 	 * Use sdev->inquiry from drivers/scsi/scsi_scan.c:scsi_alloc_sdev()
191 	 */
192 	memcpy(&wwn->vendor[0], &buf[8], sizeof(wwn->vendor));
193 	memcpy(&wwn->model[0], &buf[16], sizeof(wwn->model));
194 	memcpy(&wwn->revision[0], &buf[32], sizeof(wwn->revision));
195 }
196 
197 static int
198 pscsi_get_inquiry_vpd_serial(struct scsi_device *sdev, struct t10_wwn *wwn)
199 {
200 	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
201 	int ret;
202 
203 	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
204 	if (!buf)
205 		return -ENOMEM;
206 
207 	memset(cdb, 0, MAX_COMMAND_SIZE);
208 	cdb[0] = INQUIRY;
209 	cdb[1] = 0x01; /* Query VPD */
210 	cdb[2] = 0x80; /* Unit Serial Number */
211 	cdb[3] = (INQUIRY_VPD_SERIAL_LEN >> 8) & 0xff;
212 	cdb[4] = (INQUIRY_VPD_SERIAL_LEN & 0xff);
213 
214 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
215 			      INQUIRY_VPD_SERIAL_LEN, NULL, HZ, 1, NULL);
216 	if (ret)
217 		goto out_free;
218 
219 	snprintf(&wwn->unit_serial[0], INQUIRY_VPD_SERIAL_LEN, "%s", &buf[4]);
220 
221 	wwn->t10_dev->dev_flags |= DF_FIRMWARE_VPD_UNIT_SERIAL;
222 
223 	kfree(buf);
224 	return 0;
225 
226 out_free:
227 	kfree(buf);
228 	return -EPERM;
229 }
230 
231 static void
232 pscsi_get_inquiry_vpd_device_ident(struct scsi_device *sdev,
233 		struct t10_wwn *wwn)
234 {
235 	unsigned char cdb[MAX_COMMAND_SIZE], *buf, *page_83;
236 	int ident_len, page_len, off = 4, ret;
237 	struct t10_vpd *vpd;
238 
239 	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
240 	if (!buf)
241 		return;
242 
243 	memset(cdb, 0, MAX_COMMAND_SIZE);
244 	cdb[0] = INQUIRY;
245 	cdb[1] = 0x01; /* Query VPD */
246 	cdb[2] = 0x83; /* Device Identifier */
247 	cdb[3] = (INQUIRY_VPD_DEVICE_IDENTIFIER_LEN >> 8) & 0xff;
248 	cdb[4] = (INQUIRY_VPD_DEVICE_IDENTIFIER_LEN & 0xff);
249 
250 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
251 			      INQUIRY_VPD_DEVICE_IDENTIFIER_LEN,
252 			      NULL, HZ, 1, NULL);
253 	if (ret)
254 		goto out;
255 
256 	page_len = (buf[2] << 8) | buf[3];
257 	while (page_len > 0) {
258 		/* Grab a pointer to the Identification descriptor */
259 		page_83 = &buf[off];
260 		ident_len = page_83[3];
261 		if (!ident_len) {
262 			pr_err("page_83[3]: identifier"
263 					" length zero!\n");
264 			break;
265 		}
266 		pr_debug("T10 VPD Identifier Length: %d\n", ident_len);
267 
268 		vpd = kzalloc(sizeof(struct t10_vpd), GFP_KERNEL);
269 		if (!vpd) {
270 			pr_err("Unable to allocate memory for"
271 					" struct t10_vpd\n");
272 			goto out;
273 		}
274 		INIT_LIST_HEAD(&vpd->vpd_list);
275 
276 		transport_set_vpd_proto_id(vpd, page_83);
277 		transport_set_vpd_assoc(vpd, page_83);
278 
279 		if (transport_set_vpd_ident_type(vpd, page_83) < 0) {
280 			off += (ident_len + 4);
281 			page_len -= (ident_len + 4);
282 			kfree(vpd);
283 			continue;
284 		}
285 		if (transport_set_vpd_ident(vpd, page_83) < 0) {
286 			off += (ident_len + 4);
287 			page_len -= (ident_len + 4);
288 			kfree(vpd);
289 			continue;
290 		}
291 
292 		list_add_tail(&vpd->vpd_list, &wwn->t10_vpd_list);
293 		off += (ident_len + 4);
294 		page_len -= (ident_len + 4);
295 	}
296 
297 out:
298 	kfree(buf);
299 }
300 
301 static int pscsi_add_device_to_list(struct se_device *dev,
302 		struct scsi_device *sd)
303 {
304 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
305 	struct request_queue *q = sd->request_queue;
306 
307 	pdv->pdv_sd = sd;
308 
309 	if (!sd->queue_depth) {
310 		sd->queue_depth = PSCSI_DEFAULT_QUEUEDEPTH;
311 
312 		pr_err("Set broken SCSI Device %d:%d:%llu"
313 			" queue_depth to %d\n", sd->channel, sd->id,
314 				sd->lun, sd->queue_depth);
315 	}
316 
317 	dev->dev_attrib.hw_block_size = sd->sector_size;
318 	dev->dev_attrib.hw_max_sectors =
319 		min_t(int, sd->host->max_sectors, queue_max_hw_sectors(q));
320 	dev->dev_attrib.hw_queue_depth = sd->queue_depth;
321 
322 	/*
323 	 * Setup our standard INQUIRY info into se_dev->t10_wwn
324 	 */
325 	pscsi_set_inquiry_info(sd, &dev->t10_wwn);
326 
327 	/*
328 	 * Locate VPD WWN Information used for various purposes within
329 	 * the Storage Engine.
330 	 */
331 	if (!pscsi_get_inquiry_vpd_serial(sd, &dev->t10_wwn)) {
332 		/*
333 		 * If VPD Unit Serial returned GOOD status, try
334 		 * VPD Device Identification page (0x83).
335 		 */
336 		pscsi_get_inquiry_vpd_device_ident(sd, &dev->t10_wwn);
337 	}
338 
339 	/*
340 	 * For TYPE_TAPE, attempt to determine blocksize with MODE_SENSE.
341 	 */
342 	if (sd->type == TYPE_TAPE)
343 		pscsi_tape_read_blocksize(dev, sd);
344 	return 0;
345 }
346 
347 static struct se_device *pscsi_alloc_device(struct se_hba *hba,
348 		const char *name)
349 {
350 	struct pscsi_dev_virt *pdv;
351 
352 	pdv = kzalloc(sizeof(struct pscsi_dev_virt), GFP_KERNEL);
353 	if (!pdv) {
354 		pr_err("Unable to allocate memory for struct pscsi_dev_virt\n");
355 		return NULL;
356 	}
357 
358 	pr_debug("PSCSI: Allocated pdv: %p for %s\n", pdv, name);
359 	return &pdv->dev;
360 }
361 
362 /*
363  * Called with struct Scsi_Host->host_lock called.
364  */
365 static int pscsi_create_type_disk(struct se_device *dev, struct scsi_device *sd)
366 	__releases(sh->host_lock)
367 {
368 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
369 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
370 	struct Scsi_Host *sh = sd->host;
371 	struct block_device *bd;
372 	int ret;
373 
374 	if (scsi_device_get(sd)) {
375 		pr_err("scsi_device_get() failed for %d:%d:%d:%llu\n",
376 			sh->host_no, sd->channel, sd->id, sd->lun);
377 		spin_unlock_irq(sh->host_lock);
378 		return -EIO;
379 	}
380 	spin_unlock_irq(sh->host_lock);
381 	/*
382 	 * Claim exclusive struct block_device access to struct scsi_device
383 	 * for TYPE_DISK using supplied udev_path
384 	 */
385 	bd = blkdev_get_by_path(dev->udev_path,
386 				FMODE_WRITE|FMODE_READ|FMODE_EXCL, pdv);
387 	if (IS_ERR(bd)) {
388 		pr_err("pSCSI: blkdev_get_by_path() failed\n");
389 		scsi_device_put(sd);
390 		return PTR_ERR(bd);
391 	}
392 	pdv->pdv_bd = bd;
393 
394 	ret = pscsi_add_device_to_list(dev, sd);
395 	if (ret) {
396 		blkdev_put(pdv->pdv_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
397 		scsi_device_put(sd);
398 		return ret;
399 	}
400 
401 	pr_debug("CORE_PSCSI[%d] - Added TYPE_DISK for %d:%d:%d:%llu\n",
402 		phv->phv_host_id, sh->host_no, sd->channel, sd->id, sd->lun);
403 	return 0;
404 }
405 
406 /*
407  * Called with struct Scsi_Host->host_lock called.
408  */
409 static int pscsi_create_type_rom(struct se_device *dev, struct scsi_device *sd)
410 	__releases(sh->host_lock)
411 {
412 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
413 	struct Scsi_Host *sh = sd->host;
414 	int ret;
415 
416 	if (scsi_device_get(sd)) {
417 		pr_err("scsi_device_get() failed for %d:%d:%d:%llu\n",
418 			sh->host_no, sd->channel, sd->id, sd->lun);
419 		spin_unlock_irq(sh->host_lock);
420 		return -EIO;
421 	}
422 	spin_unlock_irq(sh->host_lock);
423 
424 	ret = pscsi_add_device_to_list(dev, sd);
425 	if (ret) {
426 		scsi_device_put(sd);
427 		return ret;
428 	}
429 	pr_debug("CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%llu\n",
430 		phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
431 		sd->channel, sd->id, sd->lun);
432 
433 	return 0;
434 }
435 
436 /*
437  * Called with struct Scsi_Host->host_lock called.
438  */
439 static int pscsi_create_type_other(struct se_device *dev,
440 		struct scsi_device *sd)
441 	__releases(sh->host_lock)
442 {
443 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
444 	struct Scsi_Host *sh = sd->host;
445 	int ret;
446 
447 	spin_unlock_irq(sh->host_lock);
448 	ret = pscsi_add_device_to_list(dev, sd);
449 	if (ret)
450 		return ret;
451 
452 	pr_debug("CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%llu\n",
453 		phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
454 		sd->channel, sd->id, sd->lun);
455 	return 0;
456 }
457 
458 static int pscsi_configure_device(struct se_device *dev)
459 {
460 	struct se_hba *hba = dev->se_hba;
461 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
462 	struct scsi_device *sd;
463 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
464 	struct Scsi_Host *sh = phv->phv_lld_host;
465 	int legacy_mode_enable = 0;
466 	int ret;
467 
468 	if (!(pdv->pdv_flags & PDF_HAS_CHANNEL_ID) ||
469 	    !(pdv->pdv_flags & PDF_HAS_TARGET_ID) ||
470 	    !(pdv->pdv_flags & PDF_HAS_LUN_ID)) {
471 		pr_err("Missing scsi_channel_id=, scsi_target_id= and"
472 			" scsi_lun_id= parameters\n");
473 		return -EINVAL;
474 	}
475 
476 	/*
477 	 * If not running in PHV_LLD_SCSI_HOST_NO mode, locate the
478 	 * struct Scsi_Host we will need to bring the TCM/pSCSI object online
479 	 */
480 	if (!sh) {
481 		if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
482 			pr_err("pSCSI: Unable to locate struct"
483 				" Scsi_Host for PHV_LLD_SCSI_HOST_NO\n");
484 			return -ENODEV;
485 		}
486 		/*
487 		 * For the newer PHV_VIRTUAL_HOST_ID struct scsi_device
488 		 * reference, we enforce that udev_path has been set
489 		 */
490 		if (!(dev->dev_flags & DF_USING_UDEV_PATH)) {
491 			pr_err("pSCSI: udev_path attribute has not"
492 				" been set before ENABLE=1\n");
493 			return -EINVAL;
494 		}
495 		/*
496 		 * If no scsi_host_id= was passed for PHV_VIRTUAL_HOST_ID,
497 		 * use the original TCM hba ID to reference Linux/SCSI Host No
498 		 * and enable for PHV_LLD_SCSI_HOST_NO mode.
499 		 */
500 		if (!(pdv->pdv_flags & PDF_HAS_VIRT_HOST_ID)) {
501 			if (hba->dev_count) {
502 				pr_err("pSCSI: Unable to set hba_mode"
503 					" with active devices\n");
504 				return -EEXIST;
505 			}
506 
507 			if (pscsi_pmode_enable_hba(hba, 1) != 1)
508 				return -ENODEV;
509 
510 			legacy_mode_enable = 1;
511 			hba->hba_flags |= HBA_FLAGS_PSCSI_MODE;
512 			sh = phv->phv_lld_host;
513 		} else {
514 			sh = scsi_host_lookup(pdv->pdv_host_id);
515 			if (!sh) {
516 				pr_err("pSCSI: Unable to locate"
517 					" pdv_host_id: %d\n", pdv->pdv_host_id);
518 				return -EINVAL;
519 			}
520 			pdv->pdv_lld_host = sh;
521 		}
522 	} else {
523 		if (phv->phv_mode == PHV_VIRTUAL_HOST_ID) {
524 			pr_err("pSCSI: PHV_VIRTUAL_HOST_ID set while"
525 				" struct Scsi_Host exists\n");
526 			return -EEXIST;
527 		}
528 	}
529 
530 	spin_lock_irq(sh->host_lock);
531 	list_for_each_entry(sd, &sh->__devices, siblings) {
532 		if ((pdv->pdv_channel_id != sd->channel) ||
533 		    (pdv->pdv_target_id != sd->id) ||
534 		    (pdv->pdv_lun_id != sd->lun))
535 			continue;
536 		/*
537 		 * Functions will release the held struct scsi_host->host_lock
538 		 * before calling calling pscsi_add_device_to_list() to register
539 		 * struct scsi_device with target_core_mod.
540 		 */
541 		switch (sd->type) {
542 		case TYPE_DISK:
543 			ret = pscsi_create_type_disk(dev, sd);
544 			break;
545 		case TYPE_ROM:
546 			ret = pscsi_create_type_rom(dev, sd);
547 			break;
548 		default:
549 			ret = pscsi_create_type_other(dev, sd);
550 			break;
551 		}
552 
553 		if (ret) {
554 			if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
555 				scsi_host_put(sh);
556 			else if (legacy_mode_enable) {
557 				pscsi_pmode_enable_hba(hba, 0);
558 				hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
559 			}
560 			pdv->pdv_sd = NULL;
561 			return ret;
562 		}
563 		return 0;
564 	}
565 	spin_unlock_irq(sh->host_lock);
566 
567 	pr_err("pSCSI: Unable to locate %d:%d:%d:%d\n", sh->host_no,
568 		pdv->pdv_channel_id,  pdv->pdv_target_id, pdv->pdv_lun_id);
569 
570 	if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
571 		scsi_host_put(sh);
572 	else if (legacy_mode_enable) {
573 		pscsi_pmode_enable_hba(hba, 0);
574 		hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
575 	}
576 
577 	return -ENODEV;
578 }
579 
580 static void pscsi_dev_call_rcu(struct rcu_head *p)
581 {
582 	struct se_device *dev = container_of(p, struct se_device, rcu_head);
583 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
584 
585 	kfree(pdv);
586 }
587 
588 static void pscsi_free_device(struct se_device *dev)
589 {
590 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
591 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
592 	struct scsi_device *sd = pdv->pdv_sd;
593 
594 	if (sd) {
595 		/*
596 		 * Release exclusive pSCSI internal struct block_device claim for
597 		 * struct scsi_device with TYPE_DISK from pscsi_create_type_disk()
598 		 */
599 		if ((sd->type == TYPE_DISK) && pdv->pdv_bd) {
600 			blkdev_put(pdv->pdv_bd,
601 				   FMODE_WRITE|FMODE_READ|FMODE_EXCL);
602 			pdv->pdv_bd = NULL;
603 		}
604 		/*
605 		 * For HBA mode PHV_LLD_SCSI_HOST_NO, release the reference
606 		 * to struct Scsi_Host now.
607 		 */
608 		if ((phv->phv_mode == PHV_LLD_SCSI_HOST_NO) &&
609 		    (phv->phv_lld_host != NULL))
610 			scsi_host_put(phv->phv_lld_host);
611 		else if (pdv->pdv_lld_host)
612 			scsi_host_put(pdv->pdv_lld_host);
613 
614 		if ((sd->type == TYPE_DISK) || (sd->type == TYPE_ROM))
615 			scsi_device_put(sd);
616 
617 		pdv->pdv_sd = NULL;
618 	}
619 	call_rcu(&dev->rcu_head, pscsi_dev_call_rcu);
620 }
621 
622 static void pscsi_transport_complete(struct se_cmd *cmd, struct scatterlist *sg,
623 				     unsigned char *sense_buffer)
624 {
625 	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
626 	struct scsi_device *sd = pdv->pdv_sd;
627 	int result;
628 	struct pscsi_plugin_task *pt = cmd->priv;
629 	unsigned char *cdb;
630 	/*
631 	 * Special case for REPORT_LUNs handling where pscsi_plugin_task has
632 	 * not been allocated because TCM is handling the emulation directly.
633 	 */
634 	if (!pt)
635 		return;
636 
637 	cdb = &pt->pscsi_cdb[0];
638 	result = pt->pscsi_result;
639 	/*
640 	 * Hack to make sure that Write-Protect modepage is set if R/O mode is
641 	 * forced.
642 	 */
643 	if (!cmd->data_length)
644 		goto after_mode_sense;
645 
646 	if (((cdb[0] == MODE_SENSE) || (cdb[0] == MODE_SENSE_10)) &&
647 	     (status_byte(result) << 1) == SAM_STAT_GOOD) {
648 		bool read_only = target_lun_is_rdonly(cmd);
649 
650 		if (read_only) {
651 			unsigned char *buf;
652 
653 			buf = transport_kmap_data_sg(cmd);
654 			if (!buf)
655 				; /* XXX: TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE */
656 
657 			if (cdb[0] == MODE_SENSE_10) {
658 				if (!(buf[3] & 0x80))
659 					buf[3] |= 0x80;
660 			} else {
661 				if (!(buf[2] & 0x80))
662 					buf[2] |= 0x80;
663 			}
664 
665 			transport_kunmap_data_sg(cmd);
666 		}
667 	}
668 after_mode_sense:
669 
670 	if (sd->type != TYPE_TAPE || !cmd->data_length)
671 		goto after_mode_select;
672 
673 	/*
674 	 * Hack to correctly obtain the initiator requested blocksize for
675 	 * TYPE_TAPE.  Since this value is dependent upon each tape media,
676 	 * struct scsi_device->sector_size will not contain the correct value
677 	 * by default, so we go ahead and set it so
678 	 * TRANSPORT(dev)->get_blockdev() returns the correct value to the
679 	 * storage engine.
680 	 */
681 	if (((cdb[0] == MODE_SELECT) || (cdb[0] == MODE_SELECT_10)) &&
682 	      (status_byte(result) << 1) == SAM_STAT_GOOD) {
683 		unsigned char *buf;
684 		u16 bdl;
685 		u32 blocksize;
686 
687 		buf = sg_virt(&sg[0]);
688 		if (!buf) {
689 			pr_err("Unable to get buf for scatterlist\n");
690 			goto after_mode_select;
691 		}
692 
693 		if (cdb[0] == MODE_SELECT)
694 			bdl = (buf[3]);
695 		else
696 			bdl = (buf[6] << 8) | (buf[7]);
697 
698 		if (!bdl)
699 			goto after_mode_select;
700 
701 		if (cdb[0] == MODE_SELECT)
702 			blocksize = (buf[9] << 16) | (buf[10] << 8) |
703 					(buf[11]);
704 		else
705 			blocksize = (buf[13] << 16) | (buf[14] << 8) |
706 					(buf[15]);
707 
708 		sd->sector_size = blocksize;
709 	}
710 after_mode_select:
711 
712 	if (sense_buffer && (status_byte(result) & CHECK_CONDITION)) {
713 		memcpy(sense_buffer, pt->pscsi_sense, TRANSPORT_SENSE_BUFFER);
714 		cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
715 	}
716 }
717 
718 enum {
719 	Opt_scsi_host_id, Opt_scsi_channel_id, Opt_scsi_target_id,
720 	Opt_scsi_lun_id, Opt_err
721 };
722 
723 static match_table_t tokens = {
724 	{Opt_scsi_host_id, "scsi_host_id=%d"},
725 	{Opt_scsi_channel_id, "scsi_channel_id=%d"},
726 	{Opt_scsi_target_id, "scsi_target_id=%d"},
727 	{Opt_scsi_lun_id, "scsi_lun_id=%d"},
728 	{Opt_err, NULL}
729 };
730 
731 static ssize_t pscsi_set_configfs_dev_params(struct se_device *dev,
732 		const char *page, ssize_t count)
733 {
734 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
735 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
736 	char *orig, *ptr, *opts;
737 	substring_t args[MAX_OPT_ARGS];
738 	int ret = 0, arg, token;
739 
740 	opts = kstrdup(page, GFP_KERNEL);
741 	if (!opts)
742 		return -ENOMEM;
743 
744 	orig = opts;
745 
746 	while ((ptr = strsep(&opts, ",\n")) != NULL) {
747 		if (!*ptr)
748 			continue;
749 
750 		token = match_token(ptr, tokens, args);
751 		switch (token) {
752 		case Opt_scsi_host_id:
753 			if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
754 				pr_err("PSCSI[%d]: Unable to accept"
755 					" scsi_host_id while phv_mode =="
756 					" PHV_LLD_SCSI_HOST_NO\n",
757 					phv->phv_host_id);
758 				ret = -EINVAL;
759 				goto out;
760 			}
761 			ret = match_int(args, &arg);
762 			if (ret)
763 				goto out;
764 			pdv->pdv_host_id = arg;
765 			pr_debug("PSCSI[%d]: Referencing SCSI Host ID:"
766 				" %d\n", phv->phv_host_id, pdv->pdv_host_id);
767 			pdv->pdv_flags |= PDF_HAS_VIRT_HOST_ID;
768 			break;
769 		case Opt_scsi_channel_id:
770 			ret = match_int(args, &arg);
771 			if (ret)
772 				goto out;
773 			pdv->pdv_channel_id = arg;
774 			pr_debug("PSCSI[%d]: Referencing SCSI Channel"
775 				" ID: %d\n",  phv->phv_host_id,
776 				pdv->pdv_channel_id);
777 			pdv->pdv_flags |= PDF_HAS_CHANNEL_ID;
778 			break;
779 		case Opt_scsi_target_id:
780 			ret = match_int(args, &arg);
781 			if (ret)
782 				goto out;
783 			pdv->pdv_target_id = arg;
784 			pr_debug("PSCSI[%d]: Referencing SCSI Target"
785 				" ID: %d\n", phv->phv_host_id,
786 				pdv->pdv_target_id);
787 			pdv->pdv_flags |= PDF_HAS_TARGET_ID;
788 			break;
789 		case Opt_scsi_lun_id:
790 			ret = match_int(args, &arg);
791 			if (ret)
792 				goto out;
793 			pdv->pdv_lun_id = arg;
794 			pr_debug("PSCSI[%d]: Referencing SCSI LUN ID:"
795 				" %d\n", phv->phv_host_id, pdv->pdv_lun_id);
796 			pdv->pdv_flags |= PDF_HAS_LUN_ID;
797 			break;
798 		default:
799 			break;
800 		}
801 	}
802 
803 out:
804 	kfree(orig);
805 	return (!ret) ? count : ret;
806 }
807 
808 static ssize_t pscsi_show_configfs_dev_params(struct se_device *dev, char *b)
809 {
810 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
811 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
812 	struct scsi_device *sd = pdv->pdv_sd;
813 	unsigned char host_id[16];
814 	ssize_t bl;
815 	int i;
816 
817 	if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
818 		snprintf(host_id, 16, "%d", pdv->pdv_host_id);
819 	else
820 		snprintf(host_id, 16, "PHBA Mode");
821 
822 	bl = sprintf(b, "SCSI Device Bus Location:"
823 		" Channel ID: %d Target ID: %d LUN: %d Host ID: %s\n",
824 		pdv->pdv_channel_id, pdv->pdv_target_id, pdv->pdv_lun_id,
825 		host_id);
826 
827 	if (sd) {
828 		bl += sprintf(b + bl, "        ");
829 		bl += sprintf(b + bl, "Vendor: ");
830 		for (i = 0; i < 8; i++) {
831 			if (ISPRINT(sd->vendor[i]))   /* printable character? */
832 				bl += sprintf(b + bl, "%c", sd->vendor[i]);
833 			else
834 				bl += sprintf(b + bl, " ");
835 		}
836 		bl += sprintf(b + bl, " Model: ");
837 		for (i = 0; i < 16; i++) {
838 			if (ISPRINT(sd->model[i]))   /* printable character ? */
839 				bl += sprintf(b + bl, "%c", sd->model[i]);
840 			else
841 				bl += sprintf(b + bl, " ");
842 		}
843 		bl += sprintf(b + bl, " Rev: ");
844 		for (i = 0; i < 4; i++) {
845 			if (ISPRINT(sd->rev[i]))   /* printable character ? */
846 				bl += sprintf(b + bl, "%c", sd->rev[i]);
847 			else
848 				bl += sprintf(b + bl, " ");
849 		}
850 		bl += sprintf(b + bl, "\n");
851 	}
852 	return bl;
853 }
854 
855 static void pscsi_bi_endio(struct bio *bio)
856 {
857 	bio_put(bio);
858 }
859 
860 static inline struct bio *pscsi_get_bio(int nr_vecs)
861 {
862 	struct bio *bio;
863 	/*
864 	 * Use bio_malloc() following the comment in for bio -> struct request
865 	 * in block/blk-core.c:blk_make_request()
866 	 */
867 	bio = bio_kmalloc(GFP_KERNEL, nr_vecs);
868 	if (!bio) {
869 		pr_err("PSCSI: bio_kmalloc() failed\n");
870 		return NULL;
871 	}
872 	bio->bi_end_io = pscsi_bi_endio;
873 
874 	return bio;
875 }
876 
877 static sense_reason_t
878 pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
879 		enum dma_data_direction data_direction, struct bio **hbio)
880 {
881 	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
882 	struct bio *bio = NULL, *tbio = NULL;
883 	struct page *page;
884 	struct scatterlist *sg;
885 	u32 data_len = cmd->data_length, i, len, bytes, off;
886 	int nr_pages = (cmd->data_length + sgl[0].offset +
887 			PAGE_SIZE - 1) >> PAGE_SHIFT;
888 	int nr_vecs = 0, rc;
889 	int rw = (data_direction == DMA_TO_DEVICE);
890 
891 	*hbio = NULL;
892 
893 	pr_debug("PSCSI: nr_pages: %d\n", nr_pages);
894 
895 	for_each_sg(sgl, sg, sgl_nents, i) {
896 		page = sg_page(sg);
897 		off = sg->offset;
898 		len = sg->length;
899 
900 		pr_debug("PSCSI: i: %d page: %p len: %d off: %d\n", i,
901 			page, len, off);
902 
903 		/*
904 		 * We only have one page of data in each sg element,
905 		 * we can not cross a page boundary.
906 		 */
907 		if (off + len > PAGE_SIZE)
908 			goto fail;
909 
910 		if (len > 0 && data_len > 0) {
911 			bytes = min_t(unsigned int, len, PAGE_SIZE - off);
912 			bytes = min(bytes, data_len);
913 
914 			if (!bio) {
915 				nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages);
916 				nr_pages -= nr_vecs;
917 				/*
918 				 * Calls bio_kmalloc() and sets bio->bi_end_io()
919 				 */
920 				bio = pscsi_get_bio(nr_vecs);
921 				if (!bio)
922 					goto fail;
923 
924 				if (rw)
925 					bio->bi_rw |= REQ_WRITE;
926 
927 				pr_debug("PSCSI: Allocated bio: %p,"
928 					" dir: %s nr_vecs: %d\n", bio,
929 					(rw) ? "rw" : "r", nr_vecs);
930 				/*
931 				 * Set *hbio pointer to handle the case:
932 				 * nr_pages > BIO_MAX_PAGES, where additional
933 				 * bios need to be added to complete a given
934 				 * command.
935 				 */
936 				if (!*hbio)
937 					*hbio = tbio = bio;
938 				else
939 					tbio = tbio->bi_next = bio;
940 			}
941 
942 			pr_debug("PSCSI: Calling bio_add_pc_page() i: %d"
943 				" bio: %p page: %p len: %d off: %d\n", i, bio,
944 				page, len, off);
945 
946 			rc = bio_add_pc_page(pdv->pdv_sd->request_queue,
947 					bio, page, bytes, off);
948 			if (rc != bytes)
949 				goto fail;
950 
951 			pr_debug("PSCSI: bio->bi_vcnt: %d nr_vecs: %d\n",
952 				bio->bi_vcnt, nr_vecs);
953 
954 			if (bio->bi_vcnt > nr_vecs) {
955 				pr_debug("PSCSI: Reached bio->bi_vcnt max:"
956 					" %d i: %d bio: %p, allocating another"
957 					" bio\n", bio->bi_vcnt, i, bio);
958 				/*
959 				 * Clear the pointer so that another bio will
960 				 * be allocated with pscsi_get_bio() above, the
961 				 * current bio has already been set *tbio and
962 				 * bio->bi_next.
963 				 */
964 				bio = NULL;
965 			}
966 
967 			data_len -= bytes;
968 		}
969 	}
970 
971 	return 0;
972 fail:
973 	while (*hbio) {
974 		bio = *hbio;
975 		*hbio = (*hbio)->bi_next;
976 		bio_endio(bio);
977 	}
978 	return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
979 }
980 
981 static sense_reason_t
982 pscsi_parse_cdb(struct se_cmd *cmd)
983 {
984 	if (cmd->se_cmd_flags & SCF_BIDI)
985 		return TCM_UNSUPPORTED_SCSI_OPCODE;
986 
987 	return passthrough_parse_cdb(cmd, pscsi_execute_cmd);
988 }
989 
990 static sense_reason_t
991 pscsi_execute_cmd(struct se_cmd *cmd)
992 {
993 	struct scatterlist *sgl = cmd->t_data_sg;
994 	u32 sgl_nents = cmd->t_data_nents;
995 	enum dma_data_direction data_direction = cmd->data_direction;
996 	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
997 	struct pscsi_plugin_task *pt;
998 	struct request *req;
999 	struct bio *hbio;
1000 	sense_reason_t ret;
1001 
1002 	/*
1003 	 * Dynamically alloc cdb space, since it may be larger than
1004 	 * TCM_MAX_COMMAND_SIZE
1005 	 */
1006 	pt = kzalloc(sizeof(*pt) + scsi_command_size(cmd->t_task_cdb), GFP_KERNEL);
1007 	if (!pt) {
1008 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1009 	}
1010 	cmd->priv = pt;
1011 
1012 	memcpy(pt->pscsi_cdb, cmd->t_task_cdb,
1013 		scsi_command_size(cmd->t_task_cdb));
1014 
1015 	if (!sgl) {
1016 		req = blk_get_request(pdv->pdv_sd->request_queue,
1017 				(data_direction == DMA_TO_DEVICE),
1018 				GFP_KERNEL);
1019 		if (IS_ERR(req)) {
1020 			pr_err("PSCSI: blk_get_request() failed\n");
1021 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1022 			goto fail;
1023 		}
1024 
1025 		blk_rq_set_block_pc(req);
1026 	} else {
1027 		BUG_ON(!cmd->data_length);
1028 
1029 		ret = pscsi_map_sg(cmd, sgl, sgl_nents, data_direction, &hbio);
1030 		if (ret)
1031 			goto fail;
1032 
1033 		req = blk_make_request(pdv->pdv_sd->request_queue, hbio,
1034 				       GFP_KERNEL);
1035 		if (IS_ERR(req)) {
1036 			pr_err("pSCSI: blk_make_request() failed\n");
1037 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1038 			goto fail_free_bio;
1039 		}
1040 	}
1041 
1042 	req->end_io = pscsi_req_done;
1043 	req->end_io_data = cmd;
1044 	req->cmd_len = scsi_command_size(pt->pscsi_cdb);
1045 	req->cmd = &pt->pscsi_cdb[0];
1046 	req->sense = &pt->pscsi_sense[0];
1047 	req->sense_len = 0;
1048 	if (pdv->pdv_sd->type == TYPE_DISK)
1049 		req->timeout = PS_TIMEOUT_DISK;
1050 	else
1051 		req->timeout = PS_TIMEOUT_OTHER;
1052 	req->retries = PS_RETRY;
1053 
1054 	blk_execute_rq_nowait(pdv->pdv_sd->request_queue, NULL, req,
1055 			(cmd->sam_task_attr == TCM_HEAD_TAG),
1056 			pscsi_req_done);
1057 
1058 	return 0;
1059 
1060 fail_free_bio:
1061 	while (hbio) {
1062 		struct bio *bio = hbio;
1063 		hbio = hbio->bi_next;
1064 		bio_endio(bio);
1065 	}
1066 	ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1067 fail:
1068 	kfree(pt);
1069 	return ret;
1070 }
1071 
1072 /*	pscsi_get_device_type():
1073  *
1074  *
1075  */
1076 static u32 pscsi_get_device_type(struct se_device *dev)
1077 {
1078 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
1079 	struct scsi_device *sd = pdv->pdv_sd;
1080 
1081 	return (sd) ? sd->type : TYPE_NO_LUN;
1082 }
1083 
1084 static sector_t pscsi_get_blocks(struct se_device *dev)
1085 {
1086 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
1087 
1088 	if (pdv->pdv_bd && pdv->pdv_bd->bd_part)
1089 		return pdv->pdv_bd->bd_part->nr_sects;
1090 
1091 	dump_stack();
1092 	return 0;
1093 }
1094 
1095 static void pscsi_req_done(struct request *req, int uptodate)
1096 {
1097 	struct se_cmd *cmd = req->end_io_data;
1098 	struct pscsi_plugin_task *pt = cmd->priv;
1099 
1100 	pt->pscsi_result = req->errors;
1101 	pt->pscsi_resid = req->resid_len;
1102 
1103 	cmd->scsi_status = status_byte(pt->pscsi_result) << 1;
1104 	if (cmd->scsi_status) {
1105 		pr_debug("PSCSI Status Byte exception at cmd: %p CDB:"
1106 			" 0x%02x Result: 0x%08x\n", cmd, pt->pscsi_cdb[0],
1107 			pt->pscsi_result);
1108 	}
1109 
1110 	switch (host_byte(pt->pscsi_result)) {
1111 	case DID_OK:
1112 		target_complete_cmd(cmd, cmd->scsi_status);
1113 		break;
1114 	default:
1115 		pr_debug("PSCSI Host Byte exception at cmd: %p CDB:"
1116 			" 0x%02x Result: 0x%08x\n", cmd, pt->pscsi_cdb[0],
1117 			pt->pscsi_result);
1118 		target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
1119 		break;
1120 	}
1121 
1122 	__blk_put_request(req->q, req);
1123 	kfree(pt);
1124 }
1125 
1126 static const struct target_backend_ops pscsi_ops = {
1127 	.name			= "pscsi",
1128 	.owner			= THIS_MODULE,
1129 	.transport_flags	= TRANSPORT_FLAG_PASSTHROUGH,
1130 	.attach_hba		= pscsi_attach_hba,
1131 	.detach_hba		= pscsi_detach_hba,
1132 	.pmode_enable_hba	= pscsi_pmode_enable_hba,
1133 	.alloc_device		= pscsi_alloc_device,
1134 	.configure_device	= pscsi_configure_device,
1135 	.free_device		= pscsi_free_device,
1136 	.transport_complete	= pscsi_transport_complete,
1137 	.parse_cdb		= pscsi_parse_cdb,
1138 	.set_configfs_dev_params = pscsi_set_configfs_dev_params,
1139 	.show_configfs_dev_params = pscsi_show_configfs_dev_params,
1140 	.get_device_type	= pscsi_get_device_type,
1141 	.get_blocks		= pscsi_get_blocks,
1142 	.tb_dev_attrib_attrs	= passthrough_attrib_attrs,
1143 };
1144 
1145 static int __init pscsi_module_init(void)
1146 {
1147 	return transport_backend_register(&pscsi_ops);
1148 }
1149 
1150 static void __exit pscsi_module_exit(void)
1151 {
1152 	target_backend_unregister(&pscsi_ops);
1153 }
1154 
1155 MODULE_DESCRIPTION("TCM PSCSI subsystem plugin");
1156 MODULE_AUTHOR("nab@Linux-iSCSI.org");
1157 MODULE_LICENSE("GPL");
1158 
1159 module_init(pscsi_module_init);
1160 module_exit(pscsi_module_exit);
1161